1. Field of the Invention
The present invention relates to a lifting mechanism for a device such as a dental chair. More specifically, the invention relates to a lifting mechanism which is adjustable in height within a relatively large height range and with this adjustability accomplished rapidly while still maintaining stability for the lifting mechanism. It should be appreciated that although the invention is described with reference to lifting a dental chair, such lifting mechanisms have other uses in a wide variety of fields other than dentistry.
2. Background of the Prior Art
Many occupations and professions such as dentistry require the subject, such as the patient to be maneuvered to various height positions while the subject is either in a sitting or reclining position. In the early days, this was accomplished manually through various types of mechanical assemblies to provide for the lifting operation. In more modern times, the manual assemblies have been replaced by power assemblies including but not limited to motor drive systems and hydraulic systems. The present invention relates to a motor driven lifting mechanism which is substantial improvement over the prior art lifting mechanisms.
In the prior art systems, the orientation of the motor provides for a limited travel of the lifting mechanism to thereby reduce the overall height adjustment of the chair. In addition, a number of the prior art systems do not provide for adequate stability, especially with the lifting mechanism extended in the maximum upward direction. The present invention is, therefore, directed to a lifting mechanism for an adjustable chair such as a dental chair which has an extended travel which travel can occur rapidly and with the stability of the system enhanced throught the entire travel.